<p> Aims: Winter rapeseed (<i>Brassica rapa</i> L. and <i>Brassica napus</i> L.) is a vital oil and ecological crop in North China, optimizing idle winter fields, enhancing soil sustainability, and reducing pathogens. Yet, the ecological benefits of its rhizosphere bacteria on soil fertility remain underexplored. Here we aim to evaluate the efficiency of rhizosphere bacteria of winter rapeseed to boost soil nutrient availability and biochemical activity. Methods: A trial compared rhizosphere and bulk soils of <i>B.rapa</i> and <i>B.napus</i> across two sites. Microbial biomass, enzymatic activity, and soil chemical properties were analyzed, with 16&#xa0;S rDNA amplicon sequencing used to assess bacterial community diversity and function. Results: Rhizosphere soils of <i>B.rapa</i> and <i>B.napus</i> showed significant higher in microbial biomass carbon (22.8%, 19.5%), nitrogen (27.4%, 31.8%), and phosphorus (11.4%, 9.8%) compared to bulk soils. Cultivation resulted in fewer bacterial alpha diversity and abundance. Soil enzyme activities varied: phosphatase, urease, invertase, and catalase rose post-planting, with <i>B.rapa</i> exhibiting higher phosphatase and urease activity, and <i>B.napus</i> showing elevated catalase. These microbial and enzymatic changes enhanced soil properties, increasing total phosphorus, available phosphorus, total nitrogen, and alkali-hydrolyzed nitrogen, while reducing salinity. Key environmental factors such as pH, available phosphorus, alkali-hydrolyzed nitrogen, total phosphorus, soil water content, organic carbon, and total nitrogen shaped bacterial community composition. Conclusions: Winter rapeseed was associated with higher rhizosphere bacterial activity and concurrently higher soil fertility indices, with species-specific effects on enzyme activity and nutrient cycling, highlighting its ecological value in Longdong rain-fed area of the Loess Plateau, Gansu Province.</p>